The U.S. Coast Guard suspended a search for a sailboat off the California coast today and conceded there is a chance the distress call that triggered a massive hunt was a hoax.

The Coast Guard received a distress signal about 5:30 p.m. Sunday reporting a sailboat was sinking and a family of four was abandoning ship.

An intense search by air and sea, deploying resources from the Coast Guard and the California National Guard, was called off today.

"We've saturated the area with multiple assets over a roughly 42 hours period, searched approximately 20,000 square miles and we have come up with no signs of distress, no debris in the water and that has led us to suspend this case, Coast Guard Chief Petty Officer Mike Lutz told ABCNews.com.

"There's always that chance [it's a hoax], but as far as we're concerned, anytime we get a call for distress, we treat it as peoples' lives are in danger and we'll treat it like that until we have reason to believe otherwise," Lutz said.

The Coast Guard appealed for help in identifying any missing boaters.

"Anybody who had family members, friends or neighbors who went out on a 29-foot sailboat, and they haven't heard from, should give us a call so we can put some of these pieces together," Lutz said.

"No one has come forward, no family, friends, loved ones have come forward and said we have some people missing," said Coast Guard Communications Officer Thomas McKenzie.

Coast Guard officials believe the boat was identified as the Charmblow, based on a crackling final distress call.

"Coast Guard, Coast Guard, we are abandoning ship. This is the [Charmblow], we are abandoning ship," a man's voice can be heard saying in a recording that was released today.

The names of those reportedly on board and their destination were unknown, however the missing were said to include a man and a woman, their 4-year-old son, and his cousin, Coast Guard Lt. Heather Lampert said.

Officials were told the boat's electronics system was failing as it took on water, making it impossible for rescuers to determine the precise location where it went down.

Rescuers initially believed the boat was sinking 65 miles from Pillar Point, just south of San Francisco, Lampert said. After reviewing radio tapes and making new calculations, Lampert said the search effort had been shifted slightly south to 65 miles off the coast of Monterey Bay.

The Coast Guard is already investigating two other hoaxes that triggered massive searches. In June 2012 they received a distress call saying a yacht carrying 20 people had exploded off the coast by Sandy Hook, N.J. That fake distress call was later linked to a similar call in May 2012 involving a Houston-based boat named the Skylark with six people aboard.

Both calls came from a land-based radio, both specifically contacted a specific Coast Guard radio channel, and both came over a VHF frequency.

Special Agent Michael Donnelly of the Coast Guard Investigative Service said at the time there were clear linguistic similarities between the calls.

Coast Guard Lt. Paul Rhynard said the current searchers are aware of the New Jersey and Texas hoaxes.

"Right now there's nothing that suggests that there's a connection," Rhynard said. "That's something that we'll take a look at."